The use of cooperating locking lugs on safety closures and containers to prevent children from gaining access to the contents of the container is well known in the prior art. Drugs, corrosive products, and antifreeze are examples of substances that are commonly packaged in containers or bottles having child-resistant closures. The closures and their complementary containers are designed to allow the user to open the container without allowing a child to open the same. For example, the user may squeeze the sides of the closure to release one or more locking lugs on the closure from corresponding locking lugs on the bottle neck. Typically, this type of closure has locking lugs on the closure and on the bottle neck that are sufficiently long that the lugs interact at least a second time as the closure is twisted open thereby preventing the user from rotating the closure any further without an additional unlocking action.
Safety closures are often provided including a flexible annular skirt having an inner annular surface thereof and a pair of opposed locking lugs projecting inwardly therefrom. A container for this type of closure has a neck portion having on an exterior surface a pair of opposed, outwardly-projecting locking lugs. The safety closure of this type is threadingly engageable on the container neck portion until the closure locking lugs pass over and beyond their respective cooperating container locking lugs, thereby causing interference therebetween and preventing removal rotation of the safety closure relative to the container neck. Removal of the safety closure from the container neck requires an individual to first overcome the interference between the cooperating locking lugs and to then concurrently apply sufficient removal rotation to the safety closure relative to the container
A push-and-turn system, typically used for pill containers, requires that the closure or cap for the pill container be pushed axially downwardly and rotated at the same time. Examples of “push-and-turn” closures are disclosed in U.S. Pat. No. 4,319,690, issued to Birrell et al. on Mar. 16, 1982, and U.S. Pat. No. 4,394,916, issued to Smalley on Jul. 26, 1983. These patents teach typical two-piece ramp and lug closures. Essentially the closure comprises an inner cap and an outer cap which are rotatably attached to one another. A plurality of lugs on one cap project towards a plurality of corresponding ramps on the opposite cap. Generally, the ramps and lugs engage each other when turned in a fastening direction such that the two caps turn in tandem. However, when the cap is rotated in an unfastening direction, the lugs tend to slide over the ramps. The outer cap turns freely from the inner cap, and the inner cap remains fastened to the container. In order to open the cap, the outer cap must be pushed downward in order to counteract the tendency of the lugs to slide over the ramps while the cap is being turned.
Another type of safety closure is taught in U.S. Pat. No. 3,716,161, issued to Julian et al. on Feb. 13, 1973. Julian et al. teaches a bayonet-type closures in which one of the closure and the container has a set of bayonet lugs and the other has a set of mating lugs so that it is necessary to urge the closure toward the container against a biasing means while applying a rotative force in order to disengage the bayonet lugs from the mating lugs to remove the closure from the container.
Each of the child resistant containers and corresponding enclosures found in the prior art are such that they must be used in combination with one another or it is economically prohibitive to interchange either the container or closure with a differently designed container or closure. This creates problems with production and inventory of containers and corresponding closures. Therefore, it is an object of the present invention to provide a safety closure and container combination wherein the closure and container may be interchanged with other existing closures and containers. Other objectives reached by the present invention will become apparent in the following descriptions.